Towel holder



FIG. 1 is a perspective view of a towel holder, showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof, the broken lines shown are for illustrative purposes only and form no part of the claimed design;

FIG. 4 is a left side elevational view thereof, the right side being a mirror image thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom view thereof. 

The ornamental design for a towel holder, as shown and described. 